Does serum neutrophil gelatinase-associated lipocalin level predict acute kidney injury in patients with acute rhabdomyolysis in the emergency department? A multicentre prospective study.

Objectives: The major complication of rhabdomyolysis is acute kidney injury (AKI), which requires prompt treatment. Currently, few biomarkers are available for the early detection of AKI. Serum neutrophil gelatinase-associated lipocalin (NGAL) has been suggested as an early biomarker for renal ischemia. However, its capacity to predict AKI in patients presenting with rhabdomyolysis in the emergency department (ED) remains unclear. The aim of this study was to evaluate the ability of NGAL to predict 48-hour AKI.

Design: Prospective, multicentre study.

Setting: Five adult EDs in France from August 2013 to December 2015.

Participants: NGAL levels were measured on ED admission in patients with rhabdomyolysis. A total of 197 patients were enrolled, and 189 (96%) were analysed, of whom 89 (47%) were women. Patients were included if they presented to the ED with rhabdomyolysis and a creatine phosphokinase (CPK) level above 1000 IU/L. Exclusion criteria were pregnancy, presentation with acute coronary syndrome, the need for iodinated contrast, chronic dialysis or recent use of nephrotoxic drugs (within 72 hours prior to the ED visit). Patients who withdrew consent or had AKI due to other causes were also excluded.

Primary and secondary outcome measures: The primary outcome was AKI at 48 hours, defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary outcomes included in-hospital mortality, length of hospital stay, admission to intensive care and the need for renal replacement therapy.

Results: Overall, 54 (29%) patients developed AKI by day 2. The area under the ROC curve (AUC-ROC) for NGAL in predicting AKI on day 2 was 0.60 (95% CI 0.51 to 0.70), with an optimal cut-off of 129 ng/mL. The sensitivity was 0.65, and specificity was 0.50. After adjustment for CPK levels, age, sex and oxygen saturation, the AUC-ROC for predicting AKI on day 2 increased slightly to 0.64 (95% CI 0.54 to 0.74).

Conclusion: NGAL has limited ability to predict day 2 AKI in patients presenting with acute rhabdomyolysis in the ED.

Trail registration number: NCT01544231.Comité de Protection des Personnes Sud Méditerranée III n°2011-A01059-32.